Airtel — 3g sim disconnected but 4g connection not activated

Address:

560048

My airtel sim card is of patna (Bihar). I upgraded my sim in bengaluru. The retailer gave me the new upgrade sim and did all the procedures. I also got a confirmation message. Sim number is also perfectly matched. After some time my old 3g sim got disconnected. But the new 4g sim is not activated. Please airtel help me resolve this issue. It is my very urgent phone number. My number is [protected] and the new sim number is[protected]u (Written on the pack). Please activate it as soon as possible.
Regards